I use a combination of two items to hold my phones including the larger Galaxy S7.
1. istabilizer (it has two standard tripod mount holes that I use it on my bike handle bar tripod mount or any tripods if I'm carrying around my phone to video things. What I like is the two side wings that hold the phone are strong and grippy and I set the whole view of the phone screen and the grips are small enough that I can access my phone side buttons without taking it out of the mount. It is $15 right now on amazon

https://www.amazon.com/iStabilizer-S...ds=istabilizer

2. for the tripod mount on my bike handle bars I use the Arkon bike camera mount and then simply spin on the istabilizer to that mount. It works great for me and very sturdy! It's $13 right now on amazon.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I too would be interested in hearing other phone mount solutions and how they work for people.